Python program to extract key-value pairs with substring in a dictionary

Given a dictionary list, extract all the dictionaries which have substring present in particular key.

Input : [{“Gfg” : “4”, “best” : “1”}, {“Gfg” : “good CS content”, “best” : “10”}], K = “Gfg”, sub_str = “CS” 
Output : [{‘Gfg’: ‘good CS content’, ‘best’: ’10’}] 
Explanation : “Gfg” has “CS” as substring value.

Input : [{“Gfg” : “4”, “best” : “1”}, {“Gfg” : “good content”, “best” : “10”}], K = “Gfg”, sub_str = “CS” 
Output : [] 
Explanation : No dictionary with “CS” as substring to “Gfg” key. 

Method #1 : Using list comprehension

This is one of the ways in which this task can be performed. In this, we iterate for all the dictionaries and check for key’s value substring presence using in operator.



Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 code to demonstrate working of
# Dictionaries with Substring values
# Using list comprehension
  
# initializing lists
test_list = [{"Gfg": "4", "best": "1"},
             {"Gfg": "good for CS", "best": "8"},
             {"Gfg": "good CS content", "best": "10"}]
  
# printing original list
print("The original list : " + str(test_list))
  
# initializing K key
K = "Gfg"
  
# initializing target value
sub_str = "CS"
  
# list comprehension to extract values with
# substring values using in operator
res = [val for val in test_list if sub_str in val[K]]
  
# printing result
print("Dictionaries with particular substring values : " + str(res))

chevron_right






                        filter_none










Output:




The original list : [{‘Gfg’: ‘4’, ‘best’: ‘1’}, {‘Gfg’: ‘good for CS’, ‘best’: ‘8’}, {‘Gfg’: ‘good CS content’, ‘best’: ’10’}]

Dictionaries with particular substring values : [{‘Gfg’: ‘good for CS’, ‘best’: ‘8’}, {‘Gfg’: ‘good CS content’, ‘best’: ’10’}]




Method #2 :  Using map() + in operator


This is yet another way in which this task can be performed. In this, we extract all the values with required substring using map() + lambda function. The in operator is used to check for substring inside the key’s value.




Python3














                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















# Python3 code to demonstrate working of 


# Dictionaries with Substring values 


# Using map() + in operator 


  


# initializing lists 


test_list = [{"Gfg": "4", "best": "1"}, 


             {"Gfg": "good for CS", "best": "8"}, 


             {"Gfg": "good CS content", "best": "10"}] 


  


# printing original list 


print("The original list : " + str(test_list)) 


  


# initializing K key 


K = "Gfg"


  


# initializing target value 


val = "CS"


  


# map() used to perform filtering 


res = list(map(lambda sub: val in sub[K], test_list)) 


res = [test_list[idx] for idx, ele in enumerate(res) if res[idx]] 


  


# printing result 


print("Dictionaries with particular substring values : " + str(res))



















                        chevron_right







                        filter_none










Output:




The original list : [{‘Gfg’: ‘4’, ‘best’: ‘1’}, {‘Gfg’: ‘good for CS’, ‘best’: ‘8’}, {‘Gfg’: ‘good CS content’, ‘best’: ’10’}]

Dictionaries with particular substring values : [{‘Gfg’: ‘good for CS’, ‘best’: ‘8’}, {‘Gfg’: ‘good CS content’, ‘best’: ’10’}]






Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.




To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.





    

        My Personal Notes
        arrow_drop_up
    

    

        
        

            
            
        

    


Recommended Posts:
manjeet_04
Check out this Author's contributed articles.
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on  the "Improve Article" button below.